You may then develop complications, especially if you’re in a high risk group, usually bronchitis or pneumonia, but sometimes tonsillitis, ear infection, sinusitis or brain inflammation.

Flu symptoms overlap with serious conditions such as meningitis and malaria.

So if you’ve been abroad, are breathless, confused or drowsy, have chest pain, cough up blood, have neck stiffness or pain when looking at lights, or a rash that doesn’t disappear when pressed with a glass, you’ll need urgent medical advice.

Your GP may then decide to prescribe antivirals or antibiotics, or send you into hospital.

How to dodge flu symptoms

It’s passed on by coughing/sneezing infected droplets which land on surfaces and can be inhaled or picked up on our hands, especially in winter months when we’re socialising in crowded, poorly ventilated rooms, so avoid close contact with others.

We can help to prevent spreading flu, colds and other viruses by making sure we ‘catch it, bin it, kill it’ – always sneeze or cough into a tissue, put it in a covered bin and wash your hands afterwards.

Flu jabs

A good diet and making sure our chronic medical conditions are well controlled will help, but if we’re in an ‘at risk’ group, we should have an annual jab (which changes to match mutations), although it isn’t 100% effective.

It doesn’t contain any live virus, so can’t give you flu, although it may make you feel slightly fluey or give you a sore arm if you’ve had it before.

Check if you’re eligible for a free jab with your GP. Pharmacies can also provide NHS and private immunisations.

Who needs it?

Last year almost three-quarters of people aged over 65 years had flu jabs, but only half those in clinical at risk groups, and even fewer pregnant women and eligible children.

This year it’s recommended for those aged 65 years and over, and those aged six months to under 65 in clinical risk groups (people with poor immunity and their close contacts, and those with heart, lung, kidney, liver, or neurological disease, or diabetes).

Carers, healthcare workers, and people in long-stay residential or nursing homes are also recommended to have it, as well as all pregnant women and most children aged two to seven. Ask at your GP surgery, or visit nhs.uk and search ‘flu vaccine’ for the full list.